I've got a factory replacement HEI, and long tube headers
I've got myself an Equus 3568 digital, with full advance programming and rpm readout.
http://www.equus.com/Product/Diagnostic/timing.html
this works well with my setup, the metal trigger is great around heat areas like the headers
Timing used to be a nightmare for me... like shooting darts in the dark, and it never came out right.
someone suggested this light when I started tuning my motor. There is also the Equus 3555 Advance Timing Light, which just has a manual dial, but I suggest the digital because of the rpm readout.
I can go out and tune the timing all by myself. It's very accurate, easy to use. And I even use the rpm readout when playing with the carb. It's really handy, and eliminates the need to bring someone along to sit in the car to read out your rpms.
I also looked equivalent lights, which were in the $200 to $300 range. And with how well the Equus has held up so far, for $150 from my local store, it was a great deal.
If you're rough with tools or think it's gonna be getting bang'd and thrown around, they also make the same one with a plastic cover, and some extra features. The 5568
http://www.equus.com/Product/Detail/FAE ... 48F517AD25
I really like the idea of a Timing Advance light because it lets me tune my engine through it's whole rpm range.
- With a basic timing light, unless you have a nice harmonic balancer with over 40deg timing marks, you're really limited to just setting timing at idle, and the rest of the rpm range is a guess.